1. Field of the Invention
The present invention relates to a developing device and a developing method, which supply a developer onto a substrate prepared by forming a resist film thereon and then being subjected to an exposure process, and to a storage medium that is used for the developing method.
2. Description of the Related Art
A process for manufacturing a semiconductor device involves a photolithography process. In such a photolithography process, a resist film is formed on a substrate such as a semiconductor wafer (hereinafter merely referred to as a wafer), and then exposed and developed to form a circuit pattern in the film. A system including a coating/developing device and an exposure device (connected to the coating/developing device) is used for the photolithography process. The coating/developing device is used to perform a coating process and a development process on the resist film. The exposure device is used to expose the resist film. One type of conventional developing devices performs a development process as follows: a substrate holder that holds a horizontally-oriented wafer rotates around a vertical axis; a developer nozzle supplies a developer onto the surface of the wafer from the upper side of the wafer; the developer nozzle moves in the radial direction of the wafer (while supplying the developer onto the surface of the substrate) to form a liquid film containing the developer on the surface of the wafer.
In order that the developing device performs the development process uniformly on the surface of the wafer, it is necessary that the liquid film containing the developer be uniformly formed on the surface of the wafer or it is necessary that the developer and the wafer uniformly contact each other. Thus, a process for improving wettability of the surface of the wafer with respect to the developer is performed before the development process, or the developer (that dissolved a resist film) used for the wafer is rapidly removed, as described in JP-A-2005-210059 and JP-A-2001-284206.
When the developer is supplied onto the surface of the wafer, the developer may splatter on the surface of the wafer and be attached to the developer nozzle. In this case, the developer attached to the developer nozzle may be dry on the surface of the developer nozzle, and a solid component contained in the developer may be dropped onto the surface of the wafer and then form a particle. Thus, various methods of supplying a developer onto the surface of a wafer have been discussed in order to suppress splattering of a developer on the surface of the wafer.
The surface of a wafer (resist film) has recently become more hydrophobic (water-repellent). One of the reasons is as follows. An immersion exposure process, which is performed in the following way, has been discussed. In the immersion exposure process, a liquid such as pure water is provided between a light source for exposure (such as an irradiator (lens) that irradiates the surface of the wafer with light (e.g., argon fluoride laser light)) and the surface of a wafer (resist film). Laser light emitted by the light source has a small wavelength. The surface of the wafer is exposed to the laser light. Thus, the immersion exposure process is performed so that the pure water does not have an adverse impact on a process (heating process or development process) that is performed after the exposure process. In other words, the immersion exposure process is performed so that the pure water does not remain on the wafer after the immersion exposure process. Specifically, a highly hydrophobic resist film is used so that the surface of the wafer has high hydrophobicity in some cases. Alternatively, a hydrophobic film is formed on the surface of the resist film in some cases. In those cases, a contact angle of the pure water on the surface of the wafer may be increased to approximately 90 degrees.
In the process of developing the hydrophobic surface of the wafer, the developer may splatter due to a surface tension of the water on the surface of the wafer. As a result, the wafer and the developer may not uniformly contact with each other. It is difficult to develop such a hydrophobic wafer by means of the techniques described in JP-A-2005-210059 and JP-A-2001-284206. In addition, the developer may easily splatter on the surface of the highly hydrophobic wafer. Furthermore, when the developer and a rinse liquid are simultaneously dropped onto the surface of the wafer from the developer nozzle and a rinse nozzle in order to develop the wafer as described in JP-A-2005-210059 and JP-A-2001-284206, the developer and the rinse liquid may easily collide with each other and splatter on the surface of the wafer.